Wet wall
Wet drywall is a symptom. Name the water that made it wet.
A soft wall, bubbling paint, or a musty closet often means water has been in the cavity. Cutting a hole on day one is rarely the best first move. Ignoring it is worse.
Map the wet area before anyone cuts.
Note height, whether it is near a shower, a stack, or an exterior wall, and whether it changes after a fixture is used.
Interior plumbing versus building envelope.
A wet exterior wall after melt or rain may not be a pipe. A wet interior wall after a shower often is. Mixing those two investigations wastes visits.
Drywall is not a shutoff.
Opening the wall without stopping the source just makes a larger wet opening. Get a source plan, then open what the evidence supports.
Questions people ask
Is black spotting always mould that needs a specialist?
Staining can be several things. ProShield documents water. Remediation decisions belong to the corporation and the people they hire for that work.
Can I use a home moisture meter?
You can note a reading. It is not a source finding and it is easy to misread through paint and tile.